Delete all transaction records for a security

I made a mistake when I first entered a security and I now need to delete the security and any related transactions and reenter it correctly from scratch.

I have deleted all the applicable transactions from the portfolio overview, but a transaction still shows in the security history and I am unable to delete this.

The security does not show in the list in the portfolio overview screen but does display on the security list on the security detail view screen, where the 'added' transaction is listed in transaction history. This transaction does not appear on the transaction list for the portfolio.